I have a big JSON feed, which contains an array called Show, Place and Conserts.

Show looks like this:

"Id":"1",
"ActivityType":"",
"Name":"Some show",
"Description":""

Place looks like this:

"Id":"4",
"Name":"Some place",
"Area": ""

Conserts looks like this:

"Show":"1",
"Place":"4",
"Start":"2011-08-11T19:00:00Z"

So basically for each show and place I need to iterate through and see when their ids match in Conserts. However, when I do this it takes about a minute to iterate through everything on the device. I've used NSMutableArray to do this. I store everything from the JSON feed into Core Data.

Does anyone have a suggestion for what I can do to reduce the time on the iteration through my NSMutableArrays containing the data from Core Data?